This invention relates to novel wholly aromatic polyamide fibers of high performance characteristics, particularly, high tenacity, and relates, more specifically, to certain sulfur-containing wholly aromatic polyamide fibers which may be derived from as-spun fibers of a relatively low inherent viscosity (hereafter: I.V.).
Fibers produced from wholly aromatic polyamides have found increased utility in recent years as reinforcements in high grade reinforced plastic composites, V-belts, tires, i.e., as tire cords, and the like. For use in such applications the wholly aromatic polyamide fibers are required to have high tensile strength and modulus. According to the prior art, aromatic polyamide fibers of good strength have been produced, for example, by the use of optically anisotropic dopes of certain carbocyclic aromatic polyamides in wet spinning processes (U.S. Pat. No. 3,671,542) and by the use of aromatic polyamides of high I.V. The production of wholly aromatic polyamides of high I.V. is undesirable from an economic standpoint, however, due to the longer polymerization times, the particular reactants and the special reaction conditions that are generally required to produce such polymers.
It is an object of the present invention, therefore, to provide wholly aromatic polyamide fibers possessing a novel chemical structure having high performance characteristics.
It is an object of the present invention to provide wholly aromatic polyamide fibers of high strength which may be derived from as-spun fibers of relatively low inherent viscosity.
It is another object of the present invention to provide wholly aromatic polyamide fibers which exhibit an improved resistance to burning.
It is a further object of the present invention to provide wholly aromatic polyamide fibers which exhibit particularly good resistance to organic solvents.
These and other objects, as well as the scope, nature, and utilization of the present invention will be apparent to those skilled in the art from the following description and from the appended claims.
In Applicants' copending application (U.S. Ser. No. 726,089, now U.S. Pat. No. 4,075,269) filed concurrently herewith, entitled "Improved Processs for Producing Wholly Aromatic Polyamide Fibers of High Strength" is claimed a process whereby the fibrous material of the present invention may be formed. The disclosure of this copending application is herein incorporated by reference.